<p>Recovery of touch DNA from pipe bombs and their containers following various rendering-safe techniques</p><p>Megan Boll, BA*, Arcadia University, 450 S. Easton Rd., Glenside, PA 19038; Christian Westring, PhD, NMS Labs, 3100 Stratford Av., Willow Grove, PA 19090; Allen Stewart, MS, Swede and Airy Streets, Norristown, PA 19401 ; Jill Yeakel, MSFS, 115 Purple Heart Dr., Dover AFB, DE 19904; Heather Mazzanti, MSFS, Arcadia University, 450 S. Easton Rd., Glenside, PA 19038</p><p>Educational Objectives: </p><p>After attending this presentation, attendees will learn about the strategies used to obtain touch DNA evidence from various explosive devices and/or proximal containers following two “rendered safe” techniques.</p><p>Impact Statement: </p><p>This presentation will impact the forensic science community by introducing the new touch-DNA methods for identifying individuals associated with the assembly and/or handling of explosive devices following common strategies for safe rendering . Furthermore, it will assist bomb squads in knowing which rendering safe technique to use on improvised explosive devices and their proximal containers if the aim is to optimize the yield of DNA recovered.</p><p>Crimes involving explosive devices have been on the rise in both domestic and foreign attacks. Explosives are involved in seventy percent of terrorist events. While the types of improvised explosives vary, pipe bombs are common explosive devices that make up 30 percent of these attacks. Most recently, the two Boston marathon bombing suspects utilized a multitude of explosive devices including pipe bombs, grenades, and improvised explosive devices. Although these bombs vary in strength and sophistication, the all required manual assembly using common materials.</p><p>The ideal outcome of a bombing attempt is neutralization of the explosive device by a bomb disposal unit. There are different techniques used to render a pipe bomb safe, all of which involve opening the device in some manner to reduce pressure and prevent explosion. Until recently, pipe bombs were rendered safe by firing a high velocity clay projectile at the midpoint of the explosive. A relatively new technique using high-pressure water in place of clay has been developed. In the current study, these two techniques were compared to determine of the impacts on recoverable DNA left on the surface of the pipe bomb and its proximal container.</p><p>Thirty known subjects were asked to wear and handle a backpack for seven days. Touch-DNA samples were collected from each backpack using laboratory developed methods. Polyvinyl chloride (PVC) pipes were used to create mock pipe bombs with non-explosive materials. Pipe bombs were placed inside each backpack and were later rendered safe by the following methods: 10 were rendered safe with the use of a clay projectile, 10 were rendered safe with the use of a high pressure water technique, and 10 were sampled without being rendered safe (control samples). The end caps of the bombs, back straps, and zippers were swabbed for DNA analysis. Each sample was extracted, quantified, and analyzed short tandem repeat (STR) analysis. Due to a small sample size, no statistically significant difference was found in DNA recovery as a function of the rendering safe technique. However, preliminary quantitative data do indicate a trend favoring the clay method with respect to DNA analysis. A difference in terms of success rate of obtaining DNA profiles as a function of rendering-safe technique was observed. While only 50% of pie bomb end caps that were rendered safe with water produced partial profiles and 10% produced full profiles, 90% of pipe bomb end caps rendered safe with clay produced partial STR profiles. Work to increase sample size and DNA recovery from backpacks is currently in progress . Non-rendered safe controls demonstrated higher DNA concentrations than those rendered safe. This study demonstrates that while rendering safe techniques are necessary for ensuring safety, the approach used can have serious consequences in a case with respect to the potential for identifying a suspect. </p><p>Forensic science, DNA typing, pipe bomb</p>